A pump of this kind is described in FR-A-2 141 402, for example. Although a pump of this kind as described in the aforementioned document gives excellent results, it nevertheless has the drawback of comprising many components and of being bulky, especially in the radial direction, in particular because said mechanism is made up of three cranks coupled and synchronized together and disposed at the periphery of the pump, these cranks themselves assuring limitation of the relative circular translation movement.
An aim of the present invention is to provide a pump of the above type that does not have these drawbacks.